Improvement in obtaining coloring-matter from oak-bark



UNITED STATES PATENT ()FFICE.

CARL HINRIOHS, OF NEW YORK, N. Y.

IMPROVEMENT IN OBTAINING COLORING-MATTER FROM OAK-BARK.

' Specification forming part of Letters Patent No. 29,489, dated August 7, 1860.

To all whom it may concern:

Be it known that I, CARL HINRIGHS, of New York, in the county of New York, and in the State of New York, have invented a new and Improved Mode of Augmenting the Dyeing Qualities of Vegetable Extracts, especially that of Oak-Bark; and I do hereby declare that the following is a full and exact description thereof, accompanied by samples of the article manufactored.

I extract the dyeing properties (pigment) from the coarsely-ground barkin the accompanying sample those of black oak (Quercus m'gra) and red oak-by the application of steam in proportion of half the weight above the weight of the atmospheric pressure, say eight pounds. \Vhen this operation is finished theliquid isplaced in another vessel and mixed in proportion to the weight of the bark which I have used with ten per cent. of the following acids:

.3 of the 10% sulphuric 66% 1g muriatic 20 During the mixing it must be well stirred, letting in the steam at the same time, brought to the boiling-point, and kept so for an hour; then drawn off into a larger vessel, adding about half the quantity of cold water that there is of liquid, andlet it settle. In the course of about twelve hours the pigment has fallen to the bottom, and a bright madeira-colored liquid floats above. This is separated from the sediment, which, on account of its being impregnated with acid, must be washed. lo effect this it is placed in filtering-bags and treated with cold water till the drippings do not change the color of litmus-paper. This precipitate, after being pressed and dried, will,

} degrees.

according to the quality of the bark and the attention which has been paid during the operation, produce the result of one pound equaling one hundred to one hundred and twentyeight pounds of bark. I have even found it in making my experiments to surpass sometimes two hundred. We mayin some measure account for this when we consider that all pigments containing tanning properties form in the dyeing-liquid spongy combinations, which gradually become more adhesive and do not impart themselves fully in the material which is to be dyed, leaving always a more or less colored residue. My precipitate,in being treated after the described method, must naturally have undergone a chemical alteration, as it leaves, when used in dyeing, scarcely any colored liquid as residue, but imparts itself fully to the material dyed.

It is necessary to state that if for this pro cess iron vessels are used, such must be well leaded, as the liquid must not come. in contact with iron.

I disclaim the use of acids as heretofore applied, and confine myself to the mode of using it according to the description in my specification.

\Vhat I claim as my invention and consider a novelty is- The process of concentratingdyeing extracts to such a high degree by boiling and treating them, as described in the foregoing specification, desiring that this my invention may be secured to me by Letters Patent.

' CARL HINRIOHS.

Witnesses:

OHAs. HARDY, I. B. KEIM. 

